1. Technical Field
The invention relates in general to a wired/wireless network system, and more particularly to a wired/wireless network system capable of performing radio over fiber (RoF) operation.
2. Description of the Related Art
In the present technique, wired fiber network is advantageously with high data transmission bandwidth and is disadvantageously incapable of supporting roaming connection and with low mobility. Wireless network, however, is advantageously capable of supporting roaming connection and with high mobility and is disadvantageously with low data transmission bandwidth and low transmission speed, which is incapable of meeting the demand of multimedia data transmission speed increased with each passing day.
Thus, hybrid wired/wireless network system capable of simultaneously supporting wired and wireless network service has been developed to provide data transmission service with high transmission bandwidth and mobility. Generally speaking, radio over fiber (RoF) and wavelength division multiplexed passive optical network (WDM-PON) are employed in this kind of hybrid wired/wireless network system.
Conventionally, double side band, optical carrier suppression, and single sideband modulation approaches have been used in RoF technique for conveying microwave signals and baseband signals with optical carrier wave, so as to materialize transmissions of optical microwave signals. Fiber paths, however, are generally characterized with fiber dispersion. Therefore, conventional RoF technique employing double sideband modulation approach has the problem of signal fading resulted in low transmission quality in long transmission distance situations; conventional RoF technique employing single sideband modulation approach has the problem of signal time-shifting resulted in low and unstable transmission quality in long transmission distance situations.